Okay, first of all, I've not read the original comic, but I recognize the unashamedly literary use of rhyme, alliteration, poetry, and cultural/political history as, at least, being pure Alan Moore. The rest? Who knows? The original strip dates back to 1982, and things have changed somewhat since then. I see some serious visual homages to the film version of 1984 (another story of a British police state to which V for Vendetta owes a serious debt of gratitude), and anyone who misses the less than subtle jabs, I mean sledgehammering, of outrage re: the American socio-political climate has to be blind, deaf, AND dumb (as in stupid, not mute).
The best part of the film, hands down, was Hugo Weaving's most distinctive voice, but given that the damn mask never came off, they might as well have gone for the gold a la Star Wars, found some TRUE aural heavyweight, and given him a body double. Weaving makes a great drag queen, but without the feather boa he didn't have quite sufficient onscreen presence.
Stephen Rea made a sufficiently droopy but virtuous cop...scratched my head through the whole film trying to figure out where I'd last seen him, but not until afterward, when my father mentioned that he is Irish, did I realize he was Da in The Butcher Boy (and someone else in every Neil Jordan film ever, it seems).
As for Natalie Portman...*shudders*
There was a nice little lesbian tragic subplot in the middle. Though its inclusion betrays the story's age (If the story were written nowadays, given the cultural detente in general regarding homosexuality, you'd probably see the government rounding up all the non-Anglo-Saxons first.), it has its heart in exactly the right place. The story gave her the autonomy to resist, to choose her death and to die as an conscious example to others.
The film betrayed its "superhero" comic origins in one particular shot of V (some body double or computer animation with way more upper body tone than Weaving) emerging from the flames.
Anyway, overall, the film was nicely atmospheric. Nice mise en scene--a little futuristic in places but not ridiculously so...nor unnecessarily decaying, for that matter--some pretty shots. But if you want truly gorgeous revenge films, watch Park Chan-Wook's Old Boy. (The preview I saw of Sympathy for Lady Vengeance looked promising as well, but I can't vouch.)
Loud and unsubtle. But then, it was supposed to be. That's, I suppose, what made it as gripping a rallying cry against injustice as it was. The film was better than I expected (and a heck of a lot better than most comic book adaptations to film) but not, God I hope not, the best film of the year.